Month: January 2009

When I first bought this van new in 2004 I was quite perplexed to find that the water heater in it was very different to the one in my very old previous camper. My previous one was a combi type: your turn the tap on and it heats water as you need it, all the way to almost boiling if you want. Brilliant, if you need a cupful or enough for a shower, the heater would work away for as long as the water and gas would last.

So picking up this shiny new posh motorhome I kind of expected similar wonderful things but more modern. Nooo…not the case. In their wisdom what I had now was a water heater which was fixed under the bed and could heat 10 litres at a time. No more, no less. 10 litres or nothing. So if you want a half a litre to wash some plates? Sorry, gotta do 10 litres. If you want to shower then wash up then wash some clothes so you need more than 10 litres, well you have to use what there is then heat some more. On gas that would take about 20-30 minutes to heat the water depending on ambient temperatures. Granted it was slightly faster on mains electric but not greatly so and anyway, who wants a half hour break in between doing things? Well actually sometimes I do lol but you know what I mean.

I did use it a couple of times, but mostly to make sure it worked. After that I found it incredibly time consuming and very wasteful. So I stopped using it and simply boiled the water I needed in my kettle which was invariably a half litre or so to wash a plate and a cup. The odd time I needed a bucket of hot water it only took 5 minutes to boil a 3 litre pan full of water. So there it languished, taking up space, until one winter…

…I forgot to empty it and it froze and there must have been a hairline crack because while it still worked, it leaked ever so slowly. Maybe a couple of drops per day but, how long before it gave up the ghost completely? How long before it burst and sent 10 litres of water all over the floor? So I made a fairly radical decision to take it out.

The flue grid, broken into pieces but repaired with Gorilla glue

It wasn’t as easy as you’d think. The gas pipe had to be taken off and a stop end put on. I didn’t want to rely on just the tap to keep the pipe closed so a stop end made sense. Then I had to disconnect all the electrics and make them safe. Then of course I had to reroute the water so that the cold inlet was rerouted and the hot pipe would simply come to a stop end. Finally I had to get it out. It was a bugger to dismantle but I got it out and realised it was made of a very thin metal with a cardboard sheath and a plastic top cover as insulation. Hugely inefficient and not very robust at all.

So, that was out of the way but it left a gaping hole in the back wall of the van where the flue was. I decided that I’d leave the flue assembly in place which was a metal plate, a plastic grid and a plastic weather cover. To discard these means a very large hole to fill so it made no sense and would look awful. So after some thought I came up with a plan.
I covered the hole on the inside with a square plastic rubble sack glued into place. I then taped the metal flue plate to cover all of the holes in it but cut 2 small holes less than the size of a 5p at the top and bottom.

Once that was resealed into place with silicone sealant (using the screws for the plastic grid to locate it in correct position for now) I used some expanding foam, directing the nozzle through first the bottom and then the top holes I’d made to ensure the cavity in the wall was completely filled. People claim that this stuff can burst concrete but it simply isn’t true. It does expand rapidly and sets very quickly. But here’s how strong it is: I had cut a small square about 6mm square in the duct tape that I used to wrap the metal plate. I cut 3 sides so that it acted like a flap. Once the cavity was full and the foam was beginning to come back out of both holes I wiped the excess and quickly put a small square of duct tape over the bottom flap. It stuck instantly and stayed there. Once the flow of foam had slowed through the top flap I also taped that. No more came out. The plastic on the inside stayed there without problem and barely curved outward there was so little pressure from the foam.

So, the foam appears from what I can tell to expand rapidly and get in all the corners, but without much pressure. It sets fairly quickly although I’m sure it’s best left for some time to fully cure.

The amazing Gorilla glue

Next step was to take the screws back out and use them to screw the plastic grid in place. The plastic grid had been broken literally into pieces. It’s 14 years old and constant sun and freezing makes plastic brittle, but these things cost a ridiculous £30 to replace. So I got the 8 pieces that I had and used the amazing Gorilla glue to piece it back together. After 24 hours the grid was flexing but solidly repaired so I squirted some silicone sealant into each screw hole in the van wall and then fixed the grid into place.
Originally I’d used mastic tape and although I think mastic tape is a brilliant material and works perfectly, it’s simply too thick so ends up making the majority of jobs look incredibly untidy and of course…screws don’t fit anymore. So tried and tested silicone sealant it is.

The outer cover was clean and unbroken anyway, so I simply pushed that on when everything was set the next day.

Now I have tons more storage space because the water heater took up a full half of the under bed storage. I have a nice neat job on the rear of the van and there’s no chance of that large flue hole letting cold or water in. I’m chuffed with the result.

PS: One thing to note with this particular glue is that it sets rock hard. It’s perfect for joining things and even for filling because it sets almost like epoxy. However that means for things that would bend slightly or flex it won’t be any good.